Cabling Chronicles

What is Your Loss Measurement Uncertainty?

Testing structured fiber cabling to international standards such as ISO/IEC 14763-3 has been defined. In the last few years, the question of loss (attenuation) measurement uncertainty has been raised. Since 14763-3 specifies test limits, the user of the standard may need to know the amount of uncertainty in the measurement. Experts from IEC, well-versed in fiber metrology and uncertainty calculations, were requested to provide simplified guidelines, a table of sorts, that a user such as an installer might find useful.

September 15, 2015

Tier 1 Testing using an OTDR on Installed Fiber Cabling?

The Telecommunications Industry Association (TIA) is committed, by formal consensus, to develop standards for the benefit of industry and is represented by hundreds of companies. While participating companies cooperate to develop standards, each have their commercial business interests to protect. Sometimes, these companies over-reach to meet their business goals. Fortunately, the TIA voting and balloting process works well as a means to check and balance sometimes rogue proposals.

August 20, 2015

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August 20, 2015

Testing Installed Fiber Cabling Terminated with MPO Connectors

Several published standards describe how to perform attenuation measurements on installed fiber optic cabling. However, no standard exists that provides guidance for testing installed fiber optic cabling terminated with MPO connectors. Currently, a technical report (TR) is being drafted that provides such testing guidance.

August 17, 2015

What You Need to Know About Testing BIMMF

Developed for use in data centers and enterprise network applications with a very tight loss budget, bend insensitive multimode fiber (BIMMF) is able to withstand tighter bends with substantially less signal loss than non-BIMMF.

A BIMMF design tightly confines the higher-order modes that are more likely to escape the fiber core during bending. The design achieves this by adding a specially engineered optical “trench” between the fiber core and cladding.

August 14, 2015

HOML as a Source Qualification Test

TIA adopted IEC 61280-4-1, the standard defining attenuation measurements of installed multimode fiber cabling, as ANSI/TIA 526-14-C.

In IEC 61280-4-1, the encircled flux launch is defined as normative (required) for these cases and there is no intention to change requirements in the next edition:
Case 1 - 50 μm core fiber at 850 nm,
Case 2 - 50 μm core fiber at 1300 nm,
Case 3 - 62.5 μm core fiber at 850 nm,
Case 4 - 62.5 μm core fiber at 1300 nm.

August 10, 2015

Revision to IEC 61280-4-1 Ed 2.0, Fibre-optic communication subsystem test procedure – Part 4-1: Installed cable plant – Multimode attenuation measurement

This primary international standard provides guidance for measurement of attenuation using power meters, light sources and OTDRs on 50/125 µm and 62.5 µm multimode fiber cabling that may include connectors, adapters and splices. Various test methods and cabling configurations are described. This report gives important information regarding upcoming changes for anyone needing to specify testing. Architects, Consultants and Engineers may use this information to learn of changes in IEC, anticipate customer concerns and gain insight to cabling testing trends.

August 7, 2015

Standards Update: The Four A’s of Harmonization

With ANSI/TIA being a North American standards body and ISO/IEC considered international, some often question why we need both, especially considering the similarities between the two.

But there are also plenty of differences—from terminology and spelling, to policy and codes. The good news is that with technology having made our world a much smaller place, TIA and IEC are fast at work harmonizing standards.

August 3, 2015

It’s Not You. It’s Your Tester

When it comes to testing your multimode optical fiber installation, inconsistent results can leave you confused and wondering if you are within your loss budget. And with today’s higher speed fiber links that require even tighter loss budgets, accuracy is more critical than ever.

But it doesn’t have to be this way. The launch condition of the light source you’re using to test has the greatest influence on your loss measurements. In other words, the wrong launch condition means the wrong measurements.

What you need is a properly controlled launch that is consistent and accurate—neither overfilled nor underfilled. Overfilled may leave you thinking you’ve gone over budget, while underfilled may leave you thinking you have room for more loss when—in fact—you do not.

July 21, 2015

The End of Era: Saying Goodbye to DTX

The year was 2004. The hottest mobile device was the Motorola Razr flip phone, Pierce Brosnan was still able to pull off a James Bond role, Facebook was a website nobody’s parents knew about, and The Red Sox won the World Series. It was also the same year that Fluke Networks introduced the DTX CableAnalyzer.

June 24, 2015